1. Field of the Invention
The present invention relates to a CDMA mobile communication system, and more particularly to a method and system for setting up a call in a CDMA mobile communication system.
2. Background of the Related Art
Data exchange in a CDMA mobile communication system is typically made either by circuit switching or packet switching. In circuit switching, information is exchanged by setting up a fixed communication path or a line between two mobile stations. Once the communication path is set up, the communication path is dedicated for transmission of information of one transaction, and is used as a dedicated line. Moreover, since no sub-networks interfere with the information through the communication path once the communication path is set up, circuit switching has no limitation in forms, codes, and transmission control processes.
In packet switching, information from an originating mobile station is accumulated, divided into fixed lengths, and transmitted in packets after an address of a receiver is provided.
A typical CDMA mobile communication system is provided with mobile stations (MS), base transceiver stations (BTS), base station controllers (BSC), a mobile switching center (MSC), and a home location register (HLR). The MS provides a terminal function for a subscriber to receive mobile communication service. The MS makes a random access in response to initiation of an originating signal and call, performs a home location registration and system information broadcasting, and receives an origination signal in a standby mode. It further provides a priority call connection and quality measurement of a communication link and links of adjacent cells.
The BTS makes radio access to the mobile station, and wire or wireless connection between the mobile station and the base station controller (BSC). The BSC is positioned between the BTS and the MSC, and manages and controls the BTS to perform operation management of the BTS, radio channel assignment control, determination and execution of hand over, and discontinuation of transmission and reception.
The MSC provides mobile communication service to a subscriber. The MSC provides line switching between subscribers, input-output relay call processing, handoff, paging, and roaming.
The HLR is a database center for managing a state of the subscriber, including present position information of the mobile station, and statistics and information related to various services.
FIG. 1 illustrates a related art system for setting up a call in a CDMA mobile communication system. Referring to FIG. 1, a data service network of the CDMA mobile communication system is provided with an origination side mobile station 10, a subscriber mobile terminal, first and second BTS 12 and 13 for radio interface with the origination side mobile station 10, and a BSC 16 for managing and controlling the first and second BTS 12 and 13. The network is further provided with a termination side mobile station 11, a subscriber mobile terminal, third and fourth BTS 14 and 15 for radio interface with the termination side mobile station 11, and a termination side BSC 17 for managing and controlling the third and fourth BTS 14 and 15. Next, a MSC 18 is provided for controlling a call from the origination side BSC 16 and the termination side BSC 17, and a HLR 19 is connected to the MSC 18 for storage and processing of position information for the subscriber to set up a call. The network further includes an Inter Working Function (IWF) 20 interlocked with the MSC 18 for processing a circuit data, and a PSTN/PLMN ISDN 21 connected to the MSC 18. A router 22 is provided for switching between the originating BSC 16 and the termination BSC 17, and a Packet Data Service Node (PDSN) 23 is connected to the router 22 for processing a packet data. An Internet Protocol (IP) network 24 connected to the PDSN 23 provides the Internet service, a Home Agent (HA) 25 connected to the IP network 24 manages position information on the origination side MS 10 and the termination side MS 11, and an AAA server 26 connected to the IP network 24 authenticates and confirms origination side MS 10 and termination side MS 11 that have roamed from other Internet Service providers (ISP) or a Public Land Mobile Network (PLMN).
A circuit data call or a packet data call can be provided for a data call in the CDMA mobile communication system. The circuit data in a range of 14.4 kpbs-64 Kbps is processed in interlock of the MSC 18 and the JWF 20, and the PDSN 23 provides a service to process a packet data of 144 kpbs or 384 kpbs class.
The method for processing a call in the related art CDMA mobile communication system has various problems. For example, a circuit data service requires 6 channels, each provided with a 64 Kbps channel capacity, of the MSC for supporting a 384 k class data. Such multiple channel usage requires complex call processing.
Additionally, in the packet data service, the call control required for real time data routing to anywhere on the Internet for real time data transmission between users on the Internet through the PDSN is not available. Furthermore, the packet data service made available by the PDSN is not suitable for transmitting fast data in real time between users, such as a picture telephone. Instead, it is limited to an Internet connection.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.